1. Field of the Invention
The present invention generally relates to a modular electronic image-capturing system that has dual mode of operation, and more particularly to the image-capturing system is used for an electronic camera for general photography or a transparent film image-capturing device depending on the image-forming modules attached.
2. The Related Art
Up to today, it is known to make the optical duplication of photographic film in the form of negative or diapositive transparencies by a conventional image-capturing apparatus with linear image sensor. An example of such systems is disclosed in U.S. Pat. Nos. 4,974,068, 5,088,813 and 5,872,591. In the ""068 patent, there is a film image information reading apparatus which includes adjustment means for adjusting the gain of the image. In the ""813 patent, a film scanner is disclosed which comprises: means for urging the film against the support means; the urging means contacting the film along an edge thereof, and guide means for maintaining the film substantially flat in the imaging station. The ""591 patent discloses a photographic film scanner for scanning a film strip containing a plurality of photography images.
In certain types of apparatus, for example, film scanners, the film must be scanned by the linear image sensor. However, the image-scanning system of past method take much time to scan a transparent film, and user have to browse through pictures on an additional screen, like a CRT screen or a TV. Conventional methods take many steps and much time to transform the image data to digital. Such devices, known as film scanners are often presented as computer peripheral devices with a single dedicated function, namely film recording.
On the other hand, there exists an electronic imaging device, which captures images onto a 2-dimensional electronic array sensor such as CCD (charged-coupled-device) or CMOS (complementary metal-oxide semiconductor) sensors. Such device is often used for general photography in which the image could be digitized into computer readable format for easy image processing and storage. Such device is better known as digital camera.
The object of the present invention is to provide a modular electronic image-capturing system with dual functional modes having at least two interchangeable and detachable modules which can be use for both general photography and film image capture. The output of the electronic image-capturing system could be in the form of analogue signal or digital signal.
Another object of the present invention is to provide a modular electronic image-capturing system with dual functional modes in order to apply the method of 2-dimensional image capture on transparent film. Such method eliminates the use of an otherwise complicated mechanical scanning mechanism. The 2-dimensional image recorded on the film is simultaneously captured imaged onto a 2-dimensional sensor array such as 2-dimensional CCD (charged-coupled-device) or CMOS (complementary metal-oxide semiconductor).
According to one embodiment of the invention, it is an object of the present invention to provide a modular electronic image-capturing system in which an image-forming component can be in the form of an optical lens designed for long conjugate distances for general photography.
According to another aspect of the invention, the image-forming component can be a fixture that consists of an optical lens specifically designed for short conjugate distance. The fixture also consists of a film carrier that hold and register the film. The transparent film could be in the form of a filmstrip or the film which could be mounted in a frame, similar to the common negative filmstrips and mounted diapositive transparencies respectively. In addition, the fixture also possesses an illumination device that is used to back-illuminate the film. The illumination can be provided by auxiliary light emitting elements such as but not limited to light emitting diodes, florescence discharge lamps, and inert gas discharge flash lamps. The illumination brightness or duration would be controlled by the image-capturing device. The electrical energy that powers the illumination could be supplied by a build-in energy source that resides in the image-forming fixture. Alternatively, the electrical energy could be supplied by the image-capturing device. The illumination can be in the form of redirected light originated from the electronic image-capturing device. Such configuration would require light coupling and guiding using light pipes of either solid or hollow construction. In such case, the image-forming fixture can be a passive device, which contains no electrical components. Consequently, the image-forming fixture is only attached to the image-capturing device by mechanical linkage.
A modular electronic image-capturing system with dual functional modes of the present invention includes a module which can scan a photographic film onto a 2-dimensional electronic array sensing device such as CCD (charged-coupled-device) or CMOS (complementary metal-oxide semiconductor) sensors and creates corresponding digital representations of the images, and another module which can take the digital images as the conventional digital camera.
Although the functions of the film-scanning module and a digital still camera are very different, there are substantial similarities between the two classes of devices. Both devices capture images in electronic form. Both devices require some sort of image-forming device that produces the images onto the electronic detector. Both devices possesses similar electronic signal processing components, which convert raw electronic signal generated at the sensor to output signal of certain standardized format.
For a digital camera, the image-forming device is in the form of an optical lens that is designed for long object conjugate distances. In a digital film scanner, the image-forming device is in the form of a copy lens that is designed specifically for short conjugate distances.